David dorward



(NoModeL) D. DORWARD; TUBULAR METAL-L1G POLE.

No; 470,153. Patented Mar; 1,1892;

InUEnTUr:

THE Nonmsyuzns UNrrE STATES PATENT OFFICE.

DAVID DORYVARD, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO THE RISDON IRON AND LOOOMOTIVE \VORKS, OF SAME PLACE.

TU BU LAR M ETALLIC POLE.

SPECIFICATION forming part of Letters Patent No. 470,153, dated March 1, 1892.

Application filed August 8, 1891.

T0 at whom it may concern:

Be it known that I, DAVID DOBWARD, a citizen of the United States, and aresident of the city and county of San Francisco, State of California, have invented certain new and useful Improvements in Tubular Metallic Poles; and I do hereby declare that the following is a full, clear, and exact description of the same.

My invention relates to the construction of metallic poles intended especially to support elevated electric conductors, such as telegraph, telephone, and electric -light wires. The desirability of substituting metallic for wooden poles is universally conceded, not only from their great durability, but because they can be given an ornamental appearance.

The object of my invention is to provide a sectional metallic pole of exceedingly cheap and simple construction, the sections of which can be easily put together and permanently secured, so that the pole, while it is manufactured and transported in sections, will when in place be practically a pole formed in one piece.

The invention consists principally in the improved manner of connecting and securing the sections together, and also in certain details of construction, which need not be specially mentioned here, but which are fully hereinafter described, as Well as shown in the accompanying drawings, in which Figure 1 is an elevation of the pole complete. Fig.2 is a vertical section at one of the joints. Fig. 3 is a section on the line X X of Fig. 2. I

My improved pole is composed of any desired number of metallic tubular sections. I have shown in the drawings three-of such sections intended when put together to form a pole of about thirty feet in height.

Referring to Fig. 2, which illustrates by a vertical section the union of any two of these tubular parts, A represents one section of tubing, and B an adjoining section above. Supposing the section A to be composed of a length of six-inch tubing, the adjoining section is preferably made from five-inch tubing.

Serial Ila 02,114. (No model.) 7

A rivet a is driven transversely through the tube A and firmly secured, forming a stop upon which the tube B rests when in place. Formed with the tube, or preferably shrunk upon it, is a ring I), which-closes the annular space between the two tubes at the bottom. Into the upper part of this space are driven wedges or keys V0, in order to preserve the two tubes in proper relative position and keep the tube B vertical. Three of these keys are shown in the drawings, but as many may be used as may be necessary, according to the size of the respective tubes. Thean nular space between the tubes is then tightly packed or calked, preferably with a composi tion which forms What is known as arustjoint, and is composed of iron filings or borings, sal-ammoni'ac, and water. Then this has set, the two tubes will be so firmly connected as to form practically one continuous tubular pole. The joint is covered and concealed by an ornamental sleeve 0r thimble d. I prefer to use the rust-joint described for a packing between the two tubes; but other substances or compositions may be employed instead, such as melted sulphur or lead.

The advantages of my device lie principally in its extreme simplicity, cheapness of construction, and durability. I avoid the necessity .of forming threads or any of the other expensive methods of construction now employed, and am thus enabled not only to re duce the cost, but to render it much easier to connect the tubes when placing the pole in position.

While I have described my invention as practically adapted to tubular poles for supporting electrical conductors, I do not confine myself to such use, as the method of jointing the sections may be employed in the connection of the tubes to be used for other purposes.

Having described my invention, I claim- 1. In combination, the tube A, having a stop, the tube B of smaller diameter inserted therein, a ring closing the bottom of the an-. nular space between the two tubes, and a packing in' the space above said ring, substantially as and for the purposes set forth.

2. The combination of the tube A, the tube In testimony whereof I have hereunto af- B, inserted therein and having the external fixed my signature, in the presence of two witring I) at its base, the keys 0, and a packing nesses, this 31st day of July, 1891.

between the tubes, substantially as set forth. DAVID DORWARD. 5 3. The combination, with the tube A, of the lVitnesses:

inserted tube B, and the transverse rivet a, L. W. SEELY,

forming a stop, substantially as set forth. J P. LANGHORNE. 

